Climate Sensitivity to Absorbing Tropospheric Aerosols in Experiments With a General Circulation Model

由对流层气溶胶（如碳质气溶胶和土壤尘气溶胶）吸收产生的直接辐射强迫是气候变化中最不确定的因素之一。该项目的主要目标是提高对这些吸收对流层气溶胶强迫的气候响应的理解。PI将使用NASA戈达德空间研究所大气环流模型（GCM）以及其他可用的GCM以及时间和资源允许的情况下进行敏感性实验，例如，社区气候系统模型。他将分析主要气候变量，如地表温度，降水，云量，海平面气压和地球位势高度在全球范围内的响应。将比较全球和纬向平均值、水平模式和这些变量在不同实验之间以及实验与观测之间的时间变异性。从这些分析中，PI将得出关于不确定性的结论，无论是在空间结构和在模拟当今气候的气候响应的幅度，由于辐射参数和吸收对流层气溶胶的垂直分布的不确定性。PI还将估计这些参数的准确性是必要的，以获得可靠的结果，从气候模拟与碳和土壤尘埃气溶胶。这项研究很重要，因为大气气溶胶强烈影响大气的辐射收支，关于气溶胶-辐射相互作用的新知识将提高气候建模者预测未来气候的能力。

Direct radiative forcing by absorbing tropospheric aerosols such as carbonaceous and soil dust aerosols is one of the most uncertain factors in climate change. The main objective of this project is to improve understanding of the climate response to forcing by these absorbing tropospheric aerosols for present day conditions. The PI will conduct sensitivity experiments using the NASA Goddard Institute of Space Studies General Circulation Model (GCM), plus other GCMs as available and as time and resources allow, e.g., the Community Climate System Model. He will analyze the response of main climate variables such as surface temperature, precipitation, cloud cover, sea level pressure and geopotential height on the global scale. Global and zonal averages, the horizontal patterns and the variability in time of these variables between different experiments as well as between experiments and observations, will be compared. From these analyses, the PI will draw conclusions about the uncertainty, both in the spatial structure and in the magnitude of the climate response in simulations of the present day climate due to the uncertainty in the radiative parameters and the vertical distribution of the absorbing tropospheric aerosols. The PI will also estimate what accuracy of these parameters is necessary to obtain reliable results from climate simulations with carbonaceous and soil dust aerosols. This research is important because atmospheric aerosols strongly impact the atmosphere's radiation budget and new knowledge about aerosol-radiation interactions will improve the ability of climate modelers to project future climates.